Andrew Brown was given permission to apply for a new inquest into the death of Joanne Foreman after police revealed “missed opportunities” in the original investigation.

Norwich shop worker Miss Foreman, 41, was pronounced dead at her home in St Helena Way, Horsford, on March 12, 2011 after being found by her partner.

An inquest in September 2011 heard the cause of Miss Foreman’s death was “unascertained”, although there was a suggestion she might have died from a combination of insulin and alcohol.

The coroner recorded a narrative verdict that it was not possible to reach a safe and reliable conclusion as to how she died.

But Mr Brown, 68, was unhappy with the verdict and has devoted “hundreds of hours” to find out what happened in the original probe and subsequent investigations.

The retired businessman, who lives with his wife Suzanne at The Glade, near Folgate Lane, Costessey, went to the High Court this month after being granted permission to seek a new inquest last year.

And following last month’s hearing Lord Justice Pitchford told the High Court that it was now agreed on all sides that the police investigation into Joanne’s death was inadequate.

Evidence that has come to light since the inquest had “effectively eliminated” the possibility that insulin played any significant part in Joanne’s death and the judge said that the entire inquest had therefore proceeded on a “mistaken assumption”.

The judge, sitting with Judge Peter Thornton QC, said: “While it is not possible to conclude that the verdict following a fresh inquest is likely to be different, I have reached the conclusion that, upon this common ground alone, it is in the interests of justice that a new inquest should be held.”

The judge “unhesitatingly” rejected Mr Brown’s assertions of misconduct and dishonesty by the police, an expert witness in the case and the coroner himself.

However, the judge accepted that, had Miss Foreman’s death been treated as “suspicious” from the outset, a full forensic post mortem and scene of crime procedures would have been carried out.

And he said: “The fact that this did not occur has resulted in unmerited speculation as to the possible causes of Joanne’s death.”

Mr Brown had claimed that Miss Foreman’s body was released for cremation “despite his protestations” and “he felt strongly that there was a reluctance among the officers involved to get to the bottom of Joanne’s death”.

He said that he had not received copies of post-mortem and toxicology reports and Lord Justice Pitchford acknowledged that it was “entirely understandable” that he had “felt marginalised” from the investigation and the inquest process.

Although he agreed that Mr Brown’s assertions of collusion and conspiracy between the police the coroner were “without foundation”, he concluded that the deficiencies in the inquest were “so significant that it is necessary and desirable in the interests of justice that a fresh investigation and inquest be held”.